/***********************************************************************
*                                                                      *
*               This software is part of the ast package               *
*          Copyright (c) 1989-2011 AT&T Intellectual Property          *
*                      and is licensed under the                       *
*                 Eclipse Public License, Version 1.0                  *
*                    by AT&T Intellectual Property                     *
*                                                                      *
*                A copy of the License is available at                 *
*          http://www.eclipse.org/org/documents/epl-v10.html           *
*         (with md5 checksum b35adb5213ca9657e911e9befb180842)         *
*                                                                      *
*              Information and Software Systems Research               *
*                            AT&T Research                             *
*                           Florham Park NJ                            *
*                                                                      *
*                 Glenn Fowler <gsf@research.att.com>                  *
*                                                                      *
***********************************************************************/
#pragma prototyped
/*
 * Glenn Fowler
 * AT&T Bell Laboratories
 *
 * convert a make abstract machine stream on stdin
 * to an oldmake makefile on stdout
 */

static const char usage[] =
"[-?\n@(#)$Id: mamold (AT&T Research) 1989-03-22 $\n]"
USAGE_LICENSE
"[+NAME?mamold - make abstract machine to oldmake makefile conversion filter]"
"[+DESCRIPTION?\bmamold\b reads MAM (Make Abstract Machine) target and"
"	prerequisite file descriptions from the standard input and writes"
"	an equivalent \bgmake\b(1) makefile on the standard output. Mamfiles"
"	are generated by the \b--mam\b option of \bnmake\b(1) and"
"	\bgmake\b(1).]"
"[+?Symbolic information is preserved where possible in the output makefile."
"	Comments, however, are lost in the conversion. Recursive makefiles"
"	are not converted; each makefile level must be converted separately.]"

"[d:debug?]#[level]"
"[g:graph?Verify the dependency graph but do not generate a makefile on"
"	the standard output.]"
"[h:header?Use \atext\as instead of the default for the generated makefile"
"	header.]#[text]"
"[x:omit?Omit pathnames with directory \aprefix\a.]#[prefix]"

"[+SEE ALSO?\bmamnew\b(1), \bgmake\b(1), \bnmake\b(1)]"
"[+REFERENCES]{"
"	[+A Make abstract machine, Glenn Fowler, 1994,?"
"		http://www.research.att.com/~gsf/mam/]"
"}"
;

#include <ast.h>
#include <mam.h>
#include <ctype.h>
#include <error.h>
#include <stdio.h>

#define LONGLINE	72		/* too long output line length	*/

#define A_listprereq	(A_LAST<<1)	/* prereqs listed		*/
#define A_listtarg	(A_LAST<<2)	/* listed as target		*/

struct state				/* program state		*/
{
	int		graph;		/* output dependency graph info	*/
	int		header;		/* header supplied		*/
	int		heredoc;	/* last value had <<		*/
	struct mam*	mam;		/* make abstract machine info	*/
	struct block*	omit;		/* dir prefixes to omit		*/
};

static struct state	state;

/*
 * clear listprereq for all prerequisites
 */

static void
clrprereqs(register struct rule* r)
{
	register struct list*	p;

	r->attributes &= ~A_listprereq;
	for (p = r->prereqs; p; p = p->next)
		if (p->rule->attributes & A_listprereq)
			clrprereqs(p->rule);
	for (p = r->implicit; p; p = p->next)
		if (p->rule->attributes & A_listprereq)
			clrprereqs(p->rule);
}

/*
 * dump a value that may be expanded by oldmake
 */

static int
dumpvalue(register int col, register char* s, int sep)
{
	register int	c;
	register char*	v;
	int		dollar;
	int		escape = 0;
	int		quote = 0;

	if (sep)
	{
		sfputc(sfstdout, sep);
		col++;
	}
	for (;;)
		switch (c = *s++)
		{
		case 0:
			if (sep && sep != '\t')
			{
				col = 1;
				sfputc(sfstdout, '\n');
			}
			return col;
		case ' ':
		case '\t':
			if (sep == '\t' && state.heredoc || col < LONGLINE - 8)
				goto emit;
			while (isspace(*s))
				s++;
			if (*s)
			{
				sfputr(sfstdout, " \\\n\t", -1);
				col = 8;
			}
			break;
		case '#':
			sfputr(sfstdout, "$(sharp)", -1);
			col += 8;
			break;
		case '<':
			if (sep == '\t' && *s == c)
				state.heredoc = 1;
			goto emit;
		case '\'':
			quote = !quote;
			goto emit;
		case '\\':
			if (*s != '$' && *s != '\'')
				goto emit;
			s++;
			escape = -1;
			/*FALLTHROUGH*/
		case '$':
			escape++;
			dollar = 1;
			if (isalpha(*s) || *s == '_')
			{
				for (v = s; isalnum(*v) || *v == '_'; v++);
				c = *v;
				*v = 0;
				if (getvar(state.mam->main, s))
				{
					sfprintf(sfstdout, "$(%s)", s);
					col += (v - s) + 3;
					*(s = v) = c;
					escape = 0;
					break;
				}
				*v = c;
			}
			if (escape)
			{
				escape = 0;
				if (!quote)
					switch (*s)
					{
					case '{':
						if (*(v = s + 1))
							v++;
						while (isalnum(*v) || *v == '_')
							v++;
						switch (*v)
						{
						case ':':
						case '-':
						case '+':
							break;
						default:
							dollar = 0;
							break;
						}
						break;
					case '$':
						s--;
						do
						{
							sfputc(sfstdout, '$');
							col++;
						} while (*++s == '$');
						break;
					default:
						sfputc(sfstdout, '\\');
						col++;
						break;
					}
			}
			else
				dollar = 0;
			c = '$';
			if (dollar)
			{
				sfputc(sfstdout, c);
				col++;
			}
			/*FALLTHROUGH*/
		default:
		emit:
			sfputc(sfstdout, c);
			col++;
			break;
		}
}

/*
 * dump a name keeping track of the right margin
 */

static int
dumpname(int col, char* s)
{
	register int	n;

	if (!state.graph)
	{
		n = strlen(s);
		if (col + n >= LONGLINE)
		{
			sfputr(sfstdout, " \\\n\t\t", -1);
			col = 16;
		}
		else if (col <= 1)
			col = 1;
		else
		{
			sfputc(sfstdout, ' ');
			col++;
		}
		col += n;
	}
	else if (col++ > 1)
		sfputc(sfstdout, ' ');
	dumpvalue(0, s, 0);
	return col;
}

/*
 * dump an action
 */

static void
dumpaction(register struct block* p)
{
	if (p)
	{
		state.heredoc = 0;
		for (;;)
		{
			dumpvalue(0, p->data, '\t');
			if (!(p = p->next))
				break;
			sfputr(sfstdout, "$(newline)", -1);
			if (!state.heredoc)
				sfputr(sfstdout, " \\\n", -1);
		}
		sfputc(sfstdout, '\n');
	}
}

/*
 * dump r and its implicit prerequisites
 */

static int
dumpprereqs(register int col, register struct rule* r)
{
	register struct block*	d;
	register struct list*	p;

	if (!(r->attributes & A_listprereq))
	{
		r->attributes |= A_listprereq;
		for (d = state.omit; d; d = d->next)
			if (strmatch(r->name, d->data))
				return col;
		col = dumpname(col, r->name);
		for (p = r->implicit; p; p = p->next)
			col = dumpprereqs(col, p->rule);
	}
	return col;
}

/*
 * dump the rules
 */

static void
dump(register struct rule* r)
{
	register int		col;
	register struct list*	p;

	if (!(r->attributes & (A_listtarg|A_metarule)))
	{
		r->attributes |= A_listtarg;
		if (r->action || r->prereqs)
		{
			clrprereqs(r);
			r->attributes |= A_listprereq;
			sfputc(sfstdout, '\n');
			col = dumpname(1, r->name);
			col = dumpname(col, ":");
			for (p = r->prereqs; p; p = p->next)
				if (!(p->rule->attributes & A_listprereq))
				{
					clrprereqs(p->rule);
					col = dumpprereqs(col, p->rule);
				}
			sfputc(sfstdout, '\n');
			if (!state.graph)
				dumpaction(r->action);
		}
		for (p = r->prereqs; p; p = p->next)
			if (p->rule != r)
				dump(p->rule);
		for (p = r->implicit; p; p = p->next)
			if (p->rule != r)
				dump(p->rule);
	}
}

/*
 * dump var definition
 */

static int
dumpvar(const char* an, char* av, void* handle)
{
	char*		name = (char*)an;
	struct var*	v = (struct var*)av;
	register char*	s;
	register char*	t;
	register int	c;

	NoP(handle);
	if (*v->value)
	{
		s = t = v->value;
		while (c = *t++ = *s++)
		{
			if (c == '\\')
			{
				if (!(*t++ = *s++))
					break;
			}
			else if (c == '"')
				t--;
		}
		dumpvalue(dumpname(0, name), v->value, '=');
	}
	return 0;
}

/*
 * add prefix to list of dir prefixes to omit
 */

static void
omit(char* prefix)
{
	int		n;
	struct block*	p;

	n = strlen(prefix);
	p = newof(0, struct block, 1, n + 1);
	strcpy(p->data = (char*)p + sizeof(struct block), prefix);
	strcpy(p->data + n, "*");
	p->next = state.omit;
	state.omit = p;
}

int
main(int argc, char** argv)
{
	register struct list*	p;

	NoP(argc);
	error_info.id = "mamold";
	for (;;)
	{
		switch (optget(argv, usage))
		{
		case 'd':
			error_info.trace = -opt_info.num;
			continue;
		case 'g':
			state.graph = 1;
			continue;
		case 'h':
			state.header = 1;
			sfputr(sfstdout, opt_info.arg, '\n');
			continue;
		case 'x':
			omit(opt_info.arg);
			continue;
		case '?':
			error(ERROR_USAGE|4, opt_info.arg);
			break;
		case ':':
			error(2, opt_info.arg);
			break;
		}
		break;
	}
	if (error_info.errors)
		error(ERROR_USAGE|4, "%s", optusage(NiL));

	/*
	 * initialize
	 */

	omit("/usr/include");
	omit("/");

	/*
	 * scan, collect and dump
	 */

	if (!state.graph && !state.header)
	{
		sfprintf(sfstdout, "# # oldmake makefile generated by mamold # #\n");
		sfprintf(sfstdout, "# oldmake ... null='' sharp='$(null)#' newline='$(null)\n");
		sfprintf(sfstdout, "# '\n");
		sfprintf(sfstdout, "newline=;\n");
	}
	if (!(state.mam = mamalloc()))
		error(3, "cannot initialize");
	mamvar(state.mam->main, "HOME", "");
	mamvar(state.mam->main, "newline", "");
	if (mamscan(state.mam, NiL) < 0)
		error(3, "invalid input");
	if (!state.graph)
		hashwalk(state.mam->main->vars, 0, dumpvar, NiL);
	for (p = state.mam->main->root->prereqs; p; p = p->next)
		dump(p->rule);
	exit(error_info.errors != 0);
}
